1. Field of the Invention
The present invention relates to teaching aids; and in particular to visual aids for teaching scientific biological concepts.
2. Brief Description of the Prior Art
The processes of hemopoiesis, hematocrit analyses, and identification of blood cells for white blood cell differentiation are difficult concepts for students to understand without an advanced education in biology or physiology. The ability to visually identify the presence of white blood cells in a cubic millimeter of blood and classify the white blood cells based on their appearance and population when scattered among staggering numbers (˜5 million) of very minute transparent red blood cells requires an understanding of quantitative statistics.
White blood cells defend the body against both infectious disease and foreign materials and the number of white blood cells in a sample of blood can change if a person is afflicted with a particular blood disorder. White blood cells only make up approximately 1% of blood in a healthy adult and the total number of white blood cells is further divided into several categories. The types of white blood cells include neutrophils (60-70%), eosinophils (2-4%), basophils (0.5-1%), lymphocytes (20-25%), and monocytes (3-8%). Because white blood cells are greatly outnumbered by red blood cells, it is difficult for a student, for example, to examine a blood smear under a microscope to identify a white blood cell, and even more difficult for the student to identify the type of white blood cell. If the sample is taken from a person afflicted with a blood disorder, determination of the blood disorder is impossible without first determining the type and number of blood cells present in the sample.
There is a need, therefore, for a teaching aid to assist students in understanding blood cell pathology and the quantitative concepts related to this subject.